When Ubuntu 10.10 Maverick Meerkat will be out, you will be able to upgrade as usual, by pressing Alt + F2 and entering “update-manager -d”.
But right now (Alpha 1 wasn’t even released yet!), you’ll have to tweak some things to be able to upgrade. For now there isn’t even an ISO available with Ubuntu 10.10 Maverick Meerkat.
Warning: only upgrade for testing purposes! Ubuntu 10.10 Maverick Meerkat is in very early development stages so a lot of things might not work! You have been warned!
This being said, here’s how to upgrade from Ubuntu 10.04 Lucid Lynx to Ubuntu 10.10 Maverick Meerkat:
1. Replace every “lucid” coinsurance in the sources.list file with “maverick” and run a dist-upgrade:
sudo sed -i 's/lucid/maverick/g' /etc/apt/sources.list && sudo aptitude update && sudo aptitude dist-upgrade
For more info http://ubuntulinux.co.in/blog/category/ubuntu/ubuntu-10-04/page/2/